The internal quantum efficiency of semiconductor chips when generating radiation, in particular those which are based on nitride compound semiconductor materials, often depends crucially on the operating current density with which the semiconductor chip is operated. Here, the expression “internal quantum efficiency” is understood to mean the ratio of the number of charge carriers of one type—electrons or holes—that are injected into the active region to the number of photons generated therefrom in the active region.
The greater the operating current density, particularly in the case of nitride-based semiconductor chips, the lower is the internal quantum efficiency. More efficient operation of semiconductor chips at high current densities would make it easier to generate an increased radiation power cost-effectively, without enlarging the active area, i.e. the area of the active region of the chip, with this semiconductor chip.